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Posted: 7/24/2024 8:25:08 PM EDT
I'm trying to figure out what it would take to run 50amp @ 240vac for 300feet, but the calculators I'm finding online don't seem to like these numbers. Can anyone tell me what it would take?
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Veteran of the Third Battle of Tannhauser Gate.
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[#1]
OST. I tried to do this many years ago but the answers gave me "2 gauge wire'' or some such.
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"The Creator may be seen in all the works of his hands, but none so clearly in the wise economy of the honey bee."
Ungracefully surrendering the things of youth... |
[#2]
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[Last Edit: voodoocustomz]
[#3]
I come up with #3 copper, or 1/0 aluminum.
ETA 1 conductor per phase utilizing a 3 AWG copper conductor installed Cable, Conduit (non-Steel), & Direct Burial will limit the voltage drop to 2.93% or less when supplying 50 amps for 300 feet on a 240 volt single phase system. Engineering Information 85Amps Rated ampacity of selected conductor 0.2379Ohms Resistance (Ohms per 1000 feet) 0.0470Ohms Reactance (Ohms per 1000 feet) 0.9Power Factor 7.20Maximum allowable voltage drop at 3% 7.038Actual voltage drop loss at 2.93% for the circuit |
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[#4]
Pretty good haul for 50a. What exactly is the load? Motor, sub panel?
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If life was easy nobody would quit.
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[#5]
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[#6]
Originally Posted By voodoocustomz: I come up with #3 copper, or 1/0 aluminum. ETA 1 conductor per phase utilizing a 3 AWG copper conductor installed Cable, Conduit (non-Steel), & Direct Burial will limit the voltage drop to 2.93% or less when supplying 50 amps for 300 feet on a 240 volt single phase system. Engineering Information 85Amps Rated ampacity of selected conductor 0.2379Ohms Resistance (Ohms per 1000 feet) 0.0470Ohms Reactance (Ohms per 1000 feet) 0.9Power Factor 7.20Maximum allowable voltage drop at 3% 7.038Actual voltage drop loss at 2.93% for the circuit View Quote Great info. And then I'd want the same size for the neutral since I'll be drawing rather high current on 120volt. How do I size the ground? |
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[Last Edit: zeekh]
[#7]
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“A double minded man is unstable in all his ways.” James 1:8 KJV
"Can a man who's warm understand one who's freezing?" Aleksandr Solzhenitsyn |
[#8]
Originally Posted By Imzadi: Great info. And then I'd want the same size for the neutral since I'll be drawing rather high current on 120volt. How do I size the ground? View Quote You just want a quadplex wire which will come with a smaller ground. It might be cheaper to get another pole and service installed. |
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[#9]
Originally Posted By zeekh: Not an electrician, AFAIK, ground can be 2 sizes smaller than feed wires. View Quote You’re thinking neutral/grounded conductor. Op, your ground is based going to be based on the size of breaker protecting the circuit. It doesn’t have to be resized for voltage drop like grounded conductors. For a 50a circuit it’s 10ga copper for ground. |
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[#10]
Originally Posted By Imzadi: Sub panel. Two RVs, an air conditioner, and lights. View Quote View All Quotes View All Quotes Originally Posted By Imzadi: Originally Posted By DVCER: Pretty good haul for 50a. What exactly is the load? Motor, sub panel? Sub panel. Two RVs, an air conditioner, and lights. You are going to power TWO RV's, and another A/C unit, on 50 amps? |
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[#11]
I always thought the most affordable is mobile home service entrance wire, like 2-2-2-4 AL.
https://www.lowes.com/pd/Southwire-2-2-2-4-Black-Stranded-Al-MHF-Use-2-Cable/5002300757 I don't think 2 is big enough tho. https://paigeconnected.com/calculators/wiresize-calculator https://www.southwire.com/calculator-vdrop |
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[Last Edit: diamondd817]
[#12]
6 gauge, or 4 gauge if you really want to overcompensate.
4/3 with ground. |
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[#13]
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[#14]
Originally Posted By lethe: You’re thinking neutral/grounded conductor. Op, your ground is based going to be based on the size of breaker protecting the circuit. It doesn’t have to be resized for voltage drop like grounded conductors. For a 50a circuit it’s 10ga copper for ground. View Quote View All Quotes View All Quotes Originally Posted By lethe: Originally Posted By zeekh: Not an electrician, AFAIK, ground can be 2 sizes smaller than feed wires. You’re thinking neutral/grounded conductor. Op, your ground is based going to be based on the size of breaker protecting the circuit. It doesn’t have to be resized for voltage drop like grounded conductors. For a 50a circuit it’s 10ga copper for ground. Separate neutral and grounds in a sub panel. Ground back to main panel can be 2 sizes smaller. Neutral same size as hot wires. |
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“A double minded man is unstable in all his ways.” James 1:8 KJV
"Can a man who's warm understand one who's freezing?" Aleksandr Solzhenitsyn |
[#15]
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[#16]
Originally Posted By lethe: Where are you getting that a ground can be 2 sizes smaller. It’s based on your ocpd size, not the size of your “hot” wires. View Quote View All Quotes View All Quotes Originally Posted By lethe: Originally Posted By zeekh: Separate neutral and grounds in a sub panel. Ground back to main panel can be 2 sizes smaller. Neutral same size as hot wires. Where are you getting that a ground can be 2 sizes smaller. It’s based on your ocpd size, not the size of your “hot” wires. Unsure what ocpd size is. I used #2 copper wire for 2 hots and a neutral from main panel to sub panel. #4 copper wire for ground from main panel to sub panel. Had my subpage inspected, it passed. Also had have ground rod at the sub panel. |
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“A double minded man is unstable in all his ways.” James 1:8 KJV
"Can a man who's warm understand one who's freezing?" Aleksandr Solzhenitsyn |
[#17]
Originally Posted By zeekh: Unsure what ocpd size is. I used #2 copper wire for 2 hots and a neutral from main panel to sub panel. #4 copper wire for ground from main panel to sub panel. Had my subpage inspected, it passed. Also had have ground rod at the sub panel. View Quote View All Quotes View All Quotes Originally Posted By zeekh: Originally Posted By lethe: Originally Posted By zeekh: Separate neutral and grounds in a sub panel. Ground back to main panel can be 2 sizes smaller. Neutral same size as hot wires. Where are you getting that a ground can be 2 sizes smaller. It’s based on your ocpd size, not the size of your “hot” wires. Unsure what ocpd size is. I used #2 copper wire for 2 hots and a neutral from main panel to sub panel. #4 copper wire for ground from main panel to sub panel. Had my subpage inspected, it passed. Also had have ground rod at the sub panel. OCPD = overcurrent protection device. The amperage rating of the breaker for the sub panel, will determine the minimum grounding conductor wire size. |
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[#18]
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[#19]
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[#20]
Originally Posted By zeekh: Unsure what ocpd size is. I used #2 copper wire for 2 hots and a neutral from main panel to sub panel. #4 copper wire for ground from main panel to sub panel. Had my subpage inspected, it passed. Also had have ground rod at the sub panel. View Quote You way oversized your ground. Nothing wrong with it being oversized but saying you can go two sizes smaller than the ungrounded conductors (hot) is going to get someone to fail an inspection. In some cases grounded conductors (neutrals) can be sized two sizes smaller than ungrounded conductors but that’s not the case at all for the grounding conductor. |
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[#21]
Originally Posted By lethe: Where are you getting that a ground can be 2 sizes smaller. It’s based on your ocpd size, not the size of your “hot” wires. View Quote View All Quotes View All Quotes Originally Posted By lethe: Originally Posted By zeekh: Separate neutral and grounds in a sub panel. Ground back to main panel can be 2 sizes smaller. Neutral same size as hot wires. Where are you getting that a ground can be 2 sizes smaller. It’s based on your ocpd size, not the size of your “hot” wires. Your ocpd is based on ampacity of your wire correct? |
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“A double minded man is unstable in all his ways.” James 1:8 KJV
"Can a man who's warm understand one who's freezing?" Aleksandr Solzhenitsyn |
[#22]
Originally Posted By lethe: You’re thinking neutral/grounded conductor. Op, your ground is based going to be based on the size of breaker protecting the circuit. It doesn’t have to be resized for voltage drop like grounded conductors. For a 50a circuit it’s 10ga copper for ground. View Quote 250.122(B) would disagree. |
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[#23]
300' I would run #4 copper
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I aint doin nothing,but doing nothing means a lot to me.
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[#24]
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